The intent of this animal resource improvement proposal is to allow the University to oontinue progress toward AAALAC accreditation which is progressing well with the help of two recent renovation grants from NIH. This proposal addresses the next project in our plan to become aocredited. A surgical suite located in the Physiology building is essential for performing 500 surgeries per year on sheep and calves. The surgical suite is adequate to perform aseptic surgery, however, the pens in the recovery room need major repairs since they have peeling paint and are rusting. The floors are wooden slats lying directly on the sealed concrete floor so cleaning feces from between and beneath the slats, while keeping the animals clean and dry, is difficult. The wooden floors cannot be maintained in a sealed condition and so are not impervious to moisture and cannot be cleaned and sanitized adequately. These pens must be replaced to allow adequate sanitation, enhance animal comfort and health, and make cleaning more efficient. Two years ago we began a service to provide investigators with viral and mycoplasmal antibody free rodents. This has been well accepted by our scientists and we have been relatively successful in maintaining VAF colonies of rats and mice. However, we have had ocasional breaks in containment. We do not have the caging equipment to provide cage-to-cage isolation which limits the spread of infectious diseases. We must upgrade to an isolator caging system to give us the required level of quality control needed to maintain disease free rodents. This proposal has the following specific aims. Specific Aim #I: To purchasing stainless steel pens with elevated floors made of vinyl coated expanded metal to replace existing pens in the Physiology building to hold sheep or calves for post surgery recovery and short term post surgical experiments. Specific Aim #2: To purchase Thoren Caging Systems, Inc. positive individually ventilated caging system racks and cages and laminar flow change stations to upgrade our ability for long term housing of viral and mycoplamsal antibody free rodents.